Ultrasonic diagnosis apparatus, medical image processing apparatus, and medical image diagnosis apparatus

ABSTRACT

According to one embodiment, an ultrasonic diagnosis apparatus includes an ultrasonic probe, an ultrasonic transmission/reception unit, a volume data generating unit, a projected image generating unit, a two dimensional region-of-interest setting unit, a specifying unit, a calculation unit and a three-dimensional region-of-interest determination unit. The specifying unit specifies cells on rays which pass through the respective pixels in the  2 D-ROI and are used to acquire a VR image. The calculation unit calculates the contribution degree of each cell based on the voxel value and opacity of each cell specified and calculates the average value of the contribution degrees of cells equal in distance from the screen of the VR image along the line-of-sight direction. The three-dimensional region-of-interest determination unit specifies the distances from the screen of the VR image which correspond to average contribution values exceeding the predetermined threshold and determines the position of the  3 D-ROI in the volume data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2010-003301, filed Jan. 8, 2010; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an ultrasonic diagnosisapparatus, medical image processing apparatus, and medical imagediagnosis apparatus.

BACKGROUND

Various types of current image diagnosis apparatuses can obtainthree-dimensional image data (to be referred to as volume datahereinafter) as well as a two-dimensional image of one slice. There havebeen proposed various display methods which allow users to easilyanalyze obtained volume data.

Methods of displaying volume data which are generally and frequentlyused include, for example, a method of displaying three arbitrary slices(to be referred to as MPR (MultiPlanar Reconstruction) imageshereinafter) perpendicular to each other and a method of displaying aprojected image from a given line-of-sight direction by volume rendering(to be referred to as VR hereinafter). The user can freely observe aregion that he/she wants to view, from a desired direction, by changingthe positions of these arbitrary slices or changing the line-of-sightdirection on a volume rendering image (to be referred to as a VR imagehereinafter).

When observing a VR image in this manner, the user sometimes loses sightof a point or region on which he/she has focused his/her attention (tobe referred to as a target region hereinafter) while rotating thedisplayed image or changing a region displayed on a VR image. Withregard to this point, marking a target region on a VR image willfacilitate analysis on volume data. A VR image is a two-dimensionalimage, where a target object with depth information is projected on onescreen. For this reason, unlike setting an ROI (Region Of Interest to bereferred to as a 2D-ROI hereinafter) in a two-dimensional slice(two-dimensional image), simply setting a 2D-ROI on a VR image will notdetermine its position in volume data. That is, it is not possible touniquely designate a target region.

When setting a three-dimensional region of interest (to be referred toas a 3D-ROI hereinafter) in volume data, the user conventionally uses amethod of designating a corresponding region in an arbitrary slice.When, for example, designating a measurement region at the time ofvolume measurement, the apparatus displays an arbitrary slice imageincluding a target stereoscopic region. The user then designates severalpoints on the displayed slice image to create a closed curve. The userrotates the volume data relative to a predetermined axis in a sliceincluding the created closed curve. The user designates points onanother slice based on the rotated volume data by a method similar tothe above operation. Repeating such a series of operations can specifythe region designated by the user in the end. In addition, since closedcurves are created on a plurality of MPR images, it is possible tocreate a 3D-ROI with a relatively complex shape. In addition, in orderto reduce the load on the user, it is possible to designate one point onan arbitrary slice and create a 3D-ROI in a spherical shape including apredetermined radius, instead of a complex shape, in volume data.

Setting a 3D-ROI in the volume data allows the user to freely observe adesired region from a desired direction without losing sight of it.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a block diagram showing the arrangement of an ultrasonicdiagnosis apparatus according to the first embodiment;

FIG. 2 is a view showing an example for explaining a ray casting methodto be used to generate a VR image according to the first embodiment;

FIGS. 3A and 3B are views respectively showing an example of a VR imageand an example of a 2D-ROI set on the VR image by an interpreting doctoror the like according to the first embodiment;

FIG. 4 is a flowchart showing a procedure for determining a 3D-ROI basedon a 2D-ROI set on a VR image in the first embodiment;

FIG. 5 is a graph of average contribution values corresponding to thedistances from the screen of a VR image along the line-of-sightdirection according to the first embodiment;

FIGS. 6A and 6B are views respectively showing an example of a VR imagegenerated with voxels whose hues are changed in a 3D-ROI and the 3D-ROIand an example of a VR image on which the line-of-sight direction ischanged according to the first embodiment;

FIG. 7 is a block diagram showing the arrangement of an ultrasonicdiagnosis apparatus according to the second embodiment;

FIG. 8 is a flowchart showing a procedure for determining a 3D-ROI basedon a three-dimensional region including a 2D-ROI as a projection of apredetermined line-of-sight direction in the second embodiment;

FIGS. 9A, 9B, and 9C are views each showing an example of athree-dimensional region moved a predetermined width at a time along theline-of-sight direction in the second embodiment;

FIG. 10 is a graph of the sums of the voxel values included in athree-dimensional region which corresponds to the distances from thescreen of a VR image to the center of the three-dimensional region alongthe line-of-sight direction according to the second embodiment;

FIG. 11 is a flowchart showing a procedure for determining a 3D-ROIbased on a three-dimensional region including a 2D-ROI as its projectionwith a predetermined line-of-sight direction and the hull surroundingthe three-dimensional region in the third embodiment; FIG. 12 is a viewshowing an example of a three-dimensional region and an example of thehull surrounding the three-dimensional region;

FIG. 13 is a graph of the differences between the sums of the voxelvalues included in a three-dimensional region which correspond to thedistances from the screen of a VR image to the center of thethree-dimensional region along the line-of-sight direction and the sumsof the voxel values included in the hull surrounding thethree-dimensional region;

FIG. 14 is a block diagram showing the arrangement of an ultrasonicdiagnosis apparatus according to the fourth embodiment;

FIG. 15 is a flowchart showing a procedure for determining a 3D-ROIbased on two line-of-sight directions which are not parallel in thefourth embodiment;

FIGS. 16A, 16B, and 16C are views each showing an example of theposition of a 3D-ROI in volume data which is determined by the shortestdistance between the first and second straight lines according to thefourth embodiment;

FIG. 17 is a flowchart showing a procedure for determining a 3D-ROIbased on a 2D-ROI set on a VR image in the fifth embodiment;

FIG. 18 is a flowchart showing a procedure for determining a 3D-ROIbased on a three-dimensional region including a 2D-ROI as its projectionwith in a predetermined line-of-sight direction in the sixth embodiment;

FIG. 19 is a flowchart showing a procedure for determining a 3D-ROIbased on a three-dimensional region including a 2D-ROI as its projectionwith a predetermined line-of-sight direction in the seventh embodiment;and

FIG. 20 is a flowchart showing a procedure for determining a 3D-ROIbased on two line-of-sight directions which are not parallel in theeighth embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, an ultrasonic diagnosisapparatus includes an ultrasonic probe, an ultrasonictransmission/reception unit, a volume data generating unit, a projectedimage generating unit, a two-dimensional region-of-interest settingunit, a specifying unit, a calculation unit, and a three-dimensionalregion-of-interest determination unit. The ultrasonictransmission/reception unit transmits an ultrasonic wave to an objectand receives a reflected wave corresponding to the transmittedultrasonic wave from the object via the ultrasonic probe, and generatesa received signal based on the received reflected wave. The volume datagenerating unit generates volume data based associated with apredetermined region of the object on the received signal. The projectedimage generating unit generates a projected image using the volume dataand a predetermined line-of-sight direction. The two-dimensionalregion-of-interest region setting unit sets a two-dimensional region ofinterest on the projected image in accordance with an instruction from auser. The specifying unit specifies a plurality of voxels in volume dataalong the predetermined line-of-sight direction for each pixel in thetwo-dimensional region of interest. The calculation unit calculates thecontribution degree of each of a plurality of voxels which contributesto the value of each pixel in a two-dimensional region of interest basedon the voxel value and opacity of each voxel. The three-dimensionalregion-of-interest determination unit determines the position of athree-dimensional region of interest in the volume data whichcorresponds to the two-dimensional region of interest based on thecontribution degrees.

An embodiment will be described below with reference to the views of theaccompanying drawing. Note that the same reference numerals denoteconstituent elements including almost the same functions andarrangements, and a repetitive description will be made only whenrequired.

First Embodiment

The first embodiment will be described below with reference to the viewsof the accompanying drawing.

FIG. 1 is a block diagram showing the arrangement of an ultrasonicdiagnosis apparatus according to this embodiment. Referring to FIG. 1,this ultrasonic diagnosis apparatus includes an ultrasonic probe 11, anultrasonic transmission/reception unit 21, a B-mode processing unit 23,a Doppler processing unit 25, a volume data generating unit 27, aprojected image generating unit 29, an interface unit 31, an inputdevice 33, an image combining unit 35, a display unit 37, atwo-dimensional region-of-interest setting unit 39, a specifying unit41, a calculation unit 43, a three-dimensional region-of-interestdetermination unit 45, a control unit 47, an internal storage device 49,and a hue changing unit 51. In addition, a network and biometric signalmeasuring units (not shown) typified by an electrocardiograph,phonocardiograph, sphygmograph, and respiration sensor may be connectedto the ultrasonic diagnosis apparatus via the interface unit 31. Notethat when the technical idea of this ultrasonic diagnosis apparatus isto be implemented by a medical image processing apparatus, the apparatushas, for example, the arrangement enclosed by the dotted line in FIG. 1.

The ultrasonic probe 11 includes piezoelectric vibrators asacoustoelectric reversible conversion elements such as piezoelectricceramics. A plurality of piezoelectric vibrators are juxtaposed andmounted on the distal end of the ultrasonic probe 11. Note that thefollowing description is based on the assumption that one vibrator formsone channel.

The ultrasonic transmission/reception unit 21 includes a rate pulsegenerator, transmission delay circuit, pulser, amplification circuit,A/D converter, beam former, and adder (not shown). The rate pulsegenerator repeatedly generates rate pulses for the formation oftransmission ultrasonic waves at a predetermined rate frequency. Thetransmission delay circuit gives each rate pulse a delay time necessaryto focus an ultrasonic wave into a beam and determine transmissiondirectivity for each channel. The pulser applies a driving pulse to eachvibrator at the timing based on this rate pulse to form an ultrasonicbeam toward a predetermined scanning line. The amplification circuitamplifies an echo signal from the object received via the ultrasonicprobe 11 for each channel. The A/D converter converts an amplified echosignal, which is an analog signal, into digital signal for each channel.The beam former gives the digital echo signals delay times necessary todetermine reception directivities. The adder then adds a plurality ofecho signals in accordance with a reception delay pattern from thecontrol unit 47. This addition enhances a reflection component from adirection corresponding to the reception directivity. The transmissiondirectivity and the reception directivity determine the syntheticdirectivity of ultrasonic transmission/reception (which determinesso-called “ultrasonic scanning lines”).

The B-mode processing unit 23 receives an echo signal from theultrasonic transmission/reception unit 21, and performs logarithmicamplification, envelope detection processing, and the like for thesignal to generate B-mode data whose signal intensity is expressed by abrightness level. The volume data generating unit 27 performspredetermined processing for the generated B-mode data.

The Doppler processing unit 25 performs Doppler processing based on anecho signal from the ultrasonic transmission/reception unit 21. TheDoppler processing is the processing of frequency-analyzing velocityinformation to extract a blood flow, tissue, and contrast medium echocomponent by the Doppler effect, and obtaining blood flow informationsuch as an average velocity, variance, and power. The volume datagenerating unit 27 performs predetermined processing for the dataincluding undergone Doppler processing (to be referred to as Dopplerdata hereinafter).

The volume data generating unit 27 arranges (arrangement processing)B-mode data from the B-mode processing unit 23 or Doppler data from theDoppler processing unit in a dedicated memory in accordance withposition information. The volume data generating unit 27 theninterpolates (interpolation processing) B-mode data or Doppler modebetween ultrasonic scanning lines. The volume data generating unit 27converts the scanning line signal for ultrasonic scanning generated bythe arrangement processing and interpolation processing into a scanningline signal in a general video format typified by a TV format. Thevolume data generating unit 27 generates volume data constituted by aplurality of voxels. Each voxel has a voxel value corresponding to theintensity of the corresponding B-mode data or Doppler data. Note thatdata before it is input to the volume data generating unit 27 will bereferred to as “raw data”.

The projected image generating unit 29 generates two-dimensional displayimage data by performing three-dimensional image processing for volumedata. Three-dimensional image processing includes VR using the raycasting method and surface rendering. Alternatively, this processing maybe MIP (Maximum Intensity Projection) or MPR processing. Assume that theprojected image generating unit 29 generates a VR image by performing VRusing the ray casting method as three-dimensional image processing.

VR will be described below with reference to FIG. 2. The volume datagenerated by the volume data generating unit 27 is constituted by aplurality of voxel data. Each voxel constituting a volume has a value ofbrightness as voxel value (voxel data). The projected image generatingunit 29 determines the opacity of each voxel with its voxel value.Assume that a voxel in FIG. 2 exists at a vertex (for example, 155) ofeach cube. When the user sets a line-of-sight direction via the inputdevice 33, the apparatus simultaneously sets a projection plane (screen)perpendicular to the line-of-sight direction. Subsequently, theprojected image generating unit 29 determines a plurality of rays whichpass through pixels in the projection plane and are parallel to theline-of-sight direction. FIG. 2 shows an example in which a given ray151 passes through part of the volume. FIG. 2 also shows an example of acell 154 including a voxel value x and opacity a calculated by linearinterpolation based on the voxel values and opacities of eight adjacentvoxels 155. Each cell exists on a ray like a cell 152 or 153 in FIG. 2.Note that a predetermined line-of-sight direction may be oneline-of-sight direction as in the case of parallel projection shown inFIG. 2, or a plurality of line-of-sight directions may be set as in thecase of perspective projection.

The projected image generating unit 29 accumulates voxel values based ona voxel value xk and opacity αk of a cell Pk on a ray Lk which isprojected as a point on the kth pixel in a projection plane. Morespecifically, an accumulated voxel value Ikout(i) passing through an ithcell Pk(i) along a ray from the projection plane can be calculated by

Ikout(i)=Ikin(i)×(1−αk(i))+xk(i)×αk(i)

where Ikin(i) is the accumulated voxel value applied from the projectionplane to the ith cell Pk(i) along the ray Lk, αk(i) is the opacity ofthe cell Pk(i), and xk(i) is the voxel value of the cell Pk(i). Notethat the accumulated voxel value Ikout(i) is an accumulated voxel valueIkin(i+1) applied to a cell Pk(i+1).

The projected image generating unit 29 accumulates opacities of aplurality of cells on a given ray while accumulating voxel values. Whena ray reaches outside the volume data or the accumulated opacity reaches1, the projected image generating unit 29 terminates this accumulationfor this ray. At this time, the accumulated voxel value is set as thevalue of a pixel on the projection plane which is associated with thisray. In the same manner, the projected image generating unit 29accumulates voxel values and opacities of a plurality of cells on otherrays. Upon acquiring the accumulated voxel values of all the pixels inthe projection plane, the projected image generating unit 29 outputs thepixel values (accumulated voxel values) in the projection plane to theimage combining unit 35.

The interface unit 31 is an interface for the input device 33, anetwork, and external storage devices and biometric signal measuringunits (none of which are shown). The interface unit 31 can transfer datasuch as ultrasonic images, analysis results, and the like obtained bythis ultrasonic diagnosis apparatus to other apparatuses through thenetwork.

The input device 33 is connected to the interface unit 31 to inputvarious kinds of commands, instruction, information, selections, andsettings from the user to this ultrasonic diagnosis apparatus. Althoughnot shown, the input device 33 includes input devices such as atrackball, switch buttons, mouse, and keyboard which are used to set a2D-ROI and the like. An input device detects the coordinates of thecursor displayed on the display screen and outputs the detectedcoordinates to the control unit 47. Note that the input device may be atouch panel covering the display screen. In this case, the input device33 detects touched/designated coordinates by, for example, anelectromagnetic induction, electro-magnetostriction, or pressuresensitive scheme, and outputs the detected coordinates to the controlunit 47. The input device 33 inputs at least the slice position or slicedirection of the display image generated by the projected imagegenerating unit 29 or at least the line-of-sight position orline-of-sight direction on the display image in accordance with theoperation of the input device by the user. The input device 33 alsosets/designates a 2D-ROI in accordance with the operation of the inputdevice by the user. When, for example, the operator operates the endbutton or FREEZE button of the input device 33, thetransmission/reception of ultrasonic waves is terminated, and theultrasonic diagnosis apparatus is set in a temporary stop state.

The image combining unit 35 combines an ultrasonic image as a projectedimage received from the projected image generating unit 29 with variouskinds of parameters, a biometric signal (e.g., an electrocardiographicwaveform, phonocardiographic waveform, sphygmographic waveform, orrespiration curve) received from a biometric signal measuring unit (notshown), a 2D-ROI set by the two-dimensional region-of-interest settingunit 39 (to be described later), scale marks, and the like, and outputsthe combined image as a video signal to the display unit 37.

The display unit 37 displays an ultrasonic image as a projected imagebased on a video signal from the image combining unit 35. FIG. 3A showsan example of a VR image displayed on the display unit 37.

The two-dimensional region-of-interest setting unit 39 sets a 2D-ROI onthe image displayed on the display unit 37 in accordance with theinstruction input by the user via the input device 33.

The specifying unit 41 specifies cells on rays which pass through therespective pixels in the 2D-ROI set by the two-dimensionalregion-of-interest setting unit 39 and are used to acquire a VR image.For example, the specifying unit 41 specifies a plurality of rays whichpass through the respective pixels in the 2D-ROI set by thetwo-dimensional region-of-interest setting unit 39 and are parallel tothe line-of-sight direction set by the user via the input device 33.Subsequently, the specifying unit 41 specifies a plurality of cells onthe plurality of specified rays.

The calculation unit 43 calculates the contribution degree of each cellwhich contributes to the value of each pixel in a 2D-ROI based on thevoxel value and opacity of each cell specified by the specifying unit41. The calculation unit 43 calculates the average value of thecontribution degrees of a plurality of cells equal in distance from thescreen of the VR image along the line-of-sight direction. This averagevalue will be referred to as an average contribution value. The internalstorage device 49 stores average contribution values in correspondencewith the information of distances from the screen of a VR image alongthe line-of-sight direction.

The three-dimensional region-of-interest determination unit 45determines whether the average contribution value calculated by thecalculation unit 43 exceeds a predetermined threshold, in the ascendingorder of the distances from the screen of the VR image. Subsequently,the three-dimensional region-of-interest determination unit 45 specifiesthe distances from the screen of the VR image which correspond toaverage contribution values exceeding the predetermined threshold forthe first time. The three-dimensional region-of-interest determinationunit 45 determines the position of the 3D-ROI in the volume data basedon the specified distances from the screen of the VR image. Thepredetermined threshold is, for example, an average contribution valueset for each lesion. Note that it is possible to store in advance, inthe internal storage device 49, predetermined thresholds for diagnostictargets, diseases, lesions, and the like as a template, and change thethresholds in accordance with the instruction issued by the user via theinput device 33, as needed. The interpreting doctor or the like canchange the size of a determined 3D-ROI via the input device 33, asneeded, while observing a displayed projected image.

The control unit 47 reads out transmission/reception conditions and anapparatus control program stored in the internal storage device 49 basedon the mode selection information, ROI setting, reception delay patternlist selection information, and transmission start/end information inputby the user via the input device 33, and controls this ultrasonicdiagnosis apparatus in accordance with these pieces of information. Thecontrol unit 47 reads out a dedicated program (a three-dimensionalregion-of-interest determination function to be described later) fordetermining the position of a 3D-ROI in volume data which corresponds tothe 2D-ROI set by the two-dimensional region-of-interest setting unit 39and a control program for implementing a predetermined imagegeneration/display operation or the like from the internal storagedevice 49, expands the programs in the memory, and executescomputation/processing and the like associated with each kind ofprocessing.

The internal storage device 49 stores a plurality of reception delaypatterns with different focal depths, a control program for theapparatus, a diagnostic protocol, various kinds of data groups such astransmission/reception conditions, the B-mode data and Doppler datagenerated by the B-mode processing unit 23 and the Doppler processingunit 25 for each scanning direction, the volume data generated by thevolume data generating unit 27, the VR images generated by the projectedimage generating unit 29, the images combined by the image combiningunit, the 2D-ROIs set by the two-dimensional region-of-interest settingunit 39, average contribution values associated with the distances fromthe screen of the VR images along the line-of-sight direction,predetermined thresholds used by the three-dimensionalregion-of-interest determination unit 45, a dedicated program forimplementing the three-dimensional region-of-interest determinationfunction, and the like.

The hue changing unit 51 changes the hues of a plurality of voxelsincluded in the 3D-ROI determined by the three-dimensionalregion-of-interest determination unit 45.

The operation of a function (to be referred to as a 3D-ROI determinationfunction hereinafter) for determining a 3D-ROI in volume data in thisultrasonic diagnosis apparatus will be described next with reference tothe flowchart shown in FIG. 4.

Before ultrasonic transmission/reception for an object, the user inputspatient information and sets and updates transmission/receptionconditions and various ultrasonic data acquisition conditions via theinput device 33. The internal storage device 49 stores these settingsand updated information. Upon completing these input/selecting/settingoperations, the doctor brings the ultrasonic probe 11 into contact withthe surface of the object at a predetermined position. The control unit47 then transmits ultrasonic waves over a plurality of heartbeats insynchronism with an ECG waveform, and receives reflected wavescorresponding to the transmitted ultrasonic waves (that is, performsultrasonic scanning) (step Sa1). Note that in step Sa1, it is possibleto transmit ultrasonic waves in synchronism with a phonocardiographicwaveform, sphygmographic waveform, respiration curve, or the like.

The received signal based on the reception of received reflected wavesis sent to the B-mode processing unit 23 or the Doppler processing unit25. B-mode data or Doppler data is generated with the received signal.The generated B-mode data or Doppler data is sent to the volume datagenerating unit 27. The volume data generating unit 27 generates volumedata with the B-mode data or Doppler data (step Sa2). A VR image isgenerated by VR using the generated volume data sent to the projectedimage generating unit 29 and the line-of-sight direction set inaccordance with the instruction issued by the user via the input device33 (step Sa3).

A 2D-ROI is set on the VR image displayed on the display unit 37 inaccordance with the instruction issued by the user via the input device33 (step Sa4). FIG. 3B is a view showing an example of setting a 2D-ROI142 on the image shown in FIG. 3A which is the VR image displayed on thedisplay unit 37.

Based on each ray used for VR in step Sa3, which passes through eachpixel in the set 2D-ROI, a plurality of cells in the volume data whichare located on the ray are specified (step Sa5). When, for example, theray 151 shown in FIG. 2 passes through pixels in the 2D-ROI, the cells152 and 153 in FIG. 2 are the cells to be specified (to be referred toas specified cells hereinafter).

The calculation unit 43 calculates a contribution degree contributing tothe value of each pixel in the 2D-ROI based on the voxel value andopacity of each specific cell calculated when the projected imagegenerating unit 29 generates a VR image (step Sa6). For example, thecalculation unit 43 can calculate a contribution degree Jm(i) of an ithcell Pm(i) on a ray Lm passing through the mth pixel in the 2D-ROIaccording to the following equation:

Jm(i)=Imout(i)−Imin(i)=Imout(i)−Imout(i−1)

where Imout(i) is an accumulated voxel value passing through the ithcell Pm(i) on the ray Lm passing through the mth pixel in the 2D-ROI seton the VR image, and Imin(i) is an accumulated voxel value applied tothe ith cell Pm(i) on the ray Lm. Note that the accumulated voxel valueImout(i−1) is the accumulated voxel value Imin(i) applied to the cellPm(i).

The calculation unit 43 calculates an average contribution value fromthe contribution degrees of a plurality of cells equal in distance(depth) from the screen of the VR image to the volume data along aplurality of rays (step Sa7). It is possible to obtain an averagecontribution value by calculating the sum of a plurality of contributiondegrees Jm(i) of an equal distance, and dividing the sum by the numberof rays, i.e., the number of pixels in the 2D-ROI.

The position of a 3D-ROI in the volume data is determined based on thedistance at which an average contribution value exceeds a predeterminedthreshold (step Sa8). FIG. 5 shows an example of average contributionvalues corresponding to distances from the screen of a VR image alongthe line-of-sight direction and the distances corresponding to averagecontribution values exceeding a predetermined threshold for thedetermination of a 3D-ROI. Referring to FIG. 5, reference numeral 161denotes the curve obtained by plotting average contribution valuescorresponding to the distances from the screen of the VR image along theline-of-sight direction; and 162, a threshold for average contributionvalues for the determination of a 3D-ROI. Reference symbol Pn denotesthe distance from the screen of the VR image at which the first averagecontribution value exceeds the predetermined threshold. Thethree-dimensional region-of-interest determination unit 45 determinesthe position of the 3D-ROI in the volume data based on the distance Pn.Assume that the position of the 3D-ROI determined based on the distancePn is the frontmost surface of the 3D-ROI. Note that reference symbol Pfdenotes an average contribution value exceeding a predeterminedthreshold at the farthest distance from the screen of the VR image alongthe line-of-sight direction on the 3D-ROI. In addition, reference symbolPc denotes a midpoint between Pn and Pf. The three-dimensionalregion-of-interest determination unit 45 can determine the position ofthe rearmost surface or center of gravity of the 3D-ROI in the volumedata based on Pf or Pc. If, for example, a 3D-ROI is spherical, it ispossible to determine the position of the center of the 3D-ROI in thevolume data based on Pc. Note that the user can set, via the inputdevice 33, information indicating which part of the 3D-ROI is made tocorrespond to the position of the 3D-ROI determined based on Pn or Pf.

It is also possible to adjust the determined 3D-ROI in accordance withthe instruction issued by the user via the input device 33.Subsequently, the apparatus changes the hues of voxels included in the3D-ROI (step Sa9). The display unit 37 displays the VR image generatedwith the voxels whose hues have been changed (step Sa10). FIG. 6A is aview showing a case of changing the hues of a plurality of voxels 143 ina 3D-ROI 144 determined for the VR image displayed by the display unit37. FIG. 6B is a view showing the VR image displayed in a line-of-sightdirection different from that in FIG. 6A. FIGS. 6A and 6B indicate thateven if the line-of-sight direction is changed, the 3D-ROI includes aregion 143 as a diagnosis target.

According to the above arrangement, the following effects can beobtained.

According to this ultrasonic diagnosis apparatus, setting a 2D-ROI onone projected image including a target region will determine a 3D-ROIincluding the target region in the volume data. Therefore, theinterpreting doctor or the like is only required to designate a 2D-ROIon one projected image including a target region or the like. Thisgreatly reduces the operation load on the doctor or the like. Inaddition, since the interpreting doctor or the like performs the aboveoperation on a displayed image, he/she need not grasp the sequentialcorrespondence between three-dimensional images and two-dimensionalimages. This prevents the interpreting doctor or the like from beingconfused. As described above, this apparatus can improve the operabilityand operation efficiency for the interpreting doctor or the like andallows him/her to easily and quickly determine a 3D-ROI.

Second Embodiment

The second embodiment will be described below with reference to theviews of the accompanying drawing.

The difference from the first embodiment is that a 3D-ROI is determinedbased on the distance from the screen of a VR image along theline-of-sight direction at which the sum of voxel values included in aset three-dimensional region becomes maximum, instead of an averagecontribution value.

FIG. 7 is a block diagram showing the arrangement of an ultrasonicdiagnosis apparatus according to the second embodiment.

The constituent elements of the first and second embodiments whichoperate differently and a three-dimensional region setting unit 42 willbe described below. Note that when the technical idea of this ultrasonicdiagnosis apparatus is to be implemented by a medical image processingapparatus, the apparatus has, for example, the arrangement enclosed bythe dotted line in FIG. 7.

The three-dimensional region setting unit 42 sets a three-dimensionalregion (to be referred to as a 3D-R (3-Dimensional Region) hereinafter),in volume data, which includes a 2D-ROI set on a VR image as aprojection region in the line-of-sight direction set at the time of thegeneration of the VR image. In other words, a projection of the 3D-R inthe line-of-sight direction includes a 2D-ROI. It is possible to set a3D-R in an arbitrary shape. Note that it is possible to select the shapeof a 3D-R from a template stored in an internal storage device 49 inadvance in accordance with the instruction issued by the user via aninput device 33. It is also possible to set the shape of a 3D-R in anarbitrary shape in accordance with the instruction issued by the uservia the input device 33.

A calculation unit 43 calculates the sum of the voxel values included ina 3D-R (to be referred to as a 3DR voxel sum hereinafter). Thecalculation unit 43 moves the 3D-R along the line-of-sight direction.The calculation unit 43 calculates a 3DR voxel sum in the moved 3D-R.The calculation unit 43 repeats the movement and calculation until the3D-R protrudes from the volume data. The internal storage device 49stores the calculated 3DR voxel sum in correspondence with the distancefrom the screen of the VR image along the line-of-sight direction. Apredetermined width is, for example, a constant number multiple of thelength of a voxel along the line-of-sight direction. Note that thiswidth can be changed in accordance with the instruction issued by theuser via an input device.

The three-dimensional region-of-interest determination unit 45 specifiesa 3DR voxel sum including the maximum value among the 3DR voxel sumsstored in the internal storage device 49 for each predetermined width.The three-dimensional region-of-interest determination unit 45determines the position of a 3D-ROI in the volume data based on thedistance from the screen of the VR image at which the maximum value ofthe 3DR voxel sum is calculated.

The operation of a function of determining a 3D-ROI (to be referred toas a 3D-ROI determination function hereafter) in volume data in thisultrasonic diagnosis apparatus will be described next with reference tothe flowchart shown in FIG. 8.

The processing in steps Sb5 to Sb9 which differs from that shown in FIG.4 which is a flowchart associated with the first embodiment will bedescribed below.

After step Sa4, the 3D-ROI determination function sets a 3D-R at aposition nearest to the screen of the VR image in the volume data (stepSb5). Note that it is possible to set the 3D-R at a position farthestfrom the screen of the VR image in the volume data. Subsequently, thisfunction calculates a 3DR voxel sum and stores it in the internalstorage device 49 in correspondence with the distance from the screen ofthe VR image along the line-of-sight direction (step Sb6). The functionthen moves the 3D-R by a predetermined width in a direction to move awayfrom (or move close to) the screen of the VR image along theline-of-sight direction (step Sb7). FIGS. 9A, 9B, and 9C show how a 3D-R72 is moved a predetermined width at a time along a line-of-sightdirection 71. That is, the 3D-R 72 moves to the positions shown in FIGS.9A, 9B, and 9C in the alphabetical order.

The 3D-ROI determination function repeats the processing in steps Sb6and Sb7 until the 3D-R protrudes from the volume data (step Sb8).

The 3D-ROI determination function determines the position of the 3D-ROIin the volume data based on the distance from the screen of the VR imageto the center of the 3D-R in which the maximum value of the 3DR voxelsum is calculated (step Sb9). FIG. 10 is a graph showing an example ofthe 3DR voxel sums corresponding to the distances from the screen of theVR image to the center of the three-dimensional region along theline-of-sight direction and the distance corresponding to the maximumvalue of the sums for the determination of a 3D-ROI. The graph in FIG.10 shows a curve 173 obtained by plotting the 3DR voxel sumscorresponding to the distances from the screen of the VR image along theline-of-sight direction. Reference symbol 3DRM denotes the maximum valueof the 3D-R; and Px, the distance from the screen of the VR image alongthe line-of-sight direction which corresponds to 3DRM for thedetermination of a 3D-ROI. The three-dimensional region-of-interestdetermination unit 45 determines the position of the 3D-ROI in thevolume data based on the distance Px. Assume that the determinedposition of the 3D-ROI is the center of gravity of the 3D-ROI. If, forexample, the 3D-ROI is spherical, the position of the center of the3D-ROI is determined in the volume data based on Px. Note that thethree-dimensional region-of-interest determination unit 45 can also setby the user with regard to which part of the 3D-ROI is made tocorrespond to the position of the 3D-ROI determined based on Px via theinput device 33.

According to the above arrangement, the following effects can beobtained.

According to this ultrasonic diagnosis apparatus, setting a 2D-ROI onone projected image including a target region will determine a 3D-ROIincluding the target region in the volume data. Therefore, theinterpreting doctor or the like is only required to designate a 2D-ROIon one projected image including a target region. This greatly reducesthe operation load on the doctor or the like. In addition, since theinterpreting doctor or the like performs the above operation on adisplayed image, he/she need not grasp the sequential correspondencebetween three-dimensional images and two-dimensional images. Thisprevents the interpreting doctor or the like from being confused. Asdescribed above, this apparatus can improve the operability andoperation efficiency for the interpreting doctor or the like and allowshim/her to easily and quickly determine a 3D-ROI.

Third Embodiment

The third embodiment will be described below with reference to the viewsof the accompanying drawing.

The difference from the first and second embodiments is that a 3D-ROI isdetermined based on the distance from the screen of a VR image along theline-of-sight direction at which the sum of the voxel values included ina set three-dimensional region differs most from the sum of the voxelvalues included in a hull surrounding the three-dimensional region.

The block diagram of the third embodiment is the same as FIG. 7 which isthe block diagram of the second embodiment. Those of the constituentelements of the first and second embodiments which operate differentlyand a three-dimensional region setting unit 42 will be described below.Note that when the technical idea of this ultrasonic diagnosis apparatusis to be implemented by a medical image processing apparatus, theapparatus has, for example, the arrangement enclosed by the dotted linein FIG. 7.

The three-dimensional region setting unit 42 sets a 3D-R and a hullsurrounding the 3D-R (to be referred to as a 3D-H (3-Dimensional Hull)hereinafter) in volume data. It is possible to set a 3D-R and 3D-H inarbitrary shapes. Note that it is possible to select the shapes of a3D-R and 3D-H from templates stored in an internal storage device 49 inadvance in accordance with the instructions issued by the user via aninput device 33. It is also possible to set the shapes of a 3D-R and3D-H in arbitrary shapes in accordance with the instructions issued bythe user via the input device 33.

A calculation unit 43 calculates the difference between the sum of voxelvalues included in 3D-R and the sum of the voxel values included in the3D-H (to be referred to as the hull sum hereinafter). The calculationunit 43 operates the 3D-R and the 3D-H to move along the line-of-sightdirection. The calculation unit 43 calculates the 3DR voxel sum in themoved 3D-R and the hull sum in the moved 3D-H. The calculation unit 43repeats the movement and calculation until the 3D-H protrudes from thevolume data. The internal storage device 49 stores the calculateddifferences in correspondence with the distances from the screen of theVR image along the line-of-sight direction.

A three-dimensional region-of-interest determination unit 45 specifiesthe maximum value of the difference from the differences stored in theinternal storage device 49 for each predetermined width. Thethree-dimensional region-of-interest determination unit 45 determinesthe position of a 3D-ROI in the volume data based on the distance fromthe screen of the VR image at which the maximum value of the differenceis calculated.

The operation of a function of determining a 3D-ROI (to be referred toas a 3D-ROI determination function hereinafter) in volume data in thisultrasonic diagnosis apparatus will be described next with reference tothe flowchart shown in FIG. 11.

The processing in steps Sc5 to Sc9 which differs from that in FIG. 4which is the flowchart associated with the first embodiment will bedescribed below.

After step Sa4, the 3D-ROI determination function sets a 3D-R and a 3D-Has the hull surrounding the 3D-R at positions nearest to the screen ofthe VR image in the volume data (step Sc5). FIG. 12 shows an example ofa 3D-R 181 and a 3D-H 182 surrounding the 3D-R. Note that it is possibleto set the 3D-R and 3D-H at positions farthest from the screen of the VRimage in the volume data. Subsequently, the 3D-ROI determinationfunction calculates the difference between the sum of voxel valuesinside the 3D-R and that inside 3D-H. The internal storage device 49stores the difference in correspondence with the distance from thescreen of the VR image along the line-of-sight direction (step Sc6).This function then moves the 3D-R and the 3D-H by a predetermined widthin a direction to move away from (or move close to) the screen of the VRimage (step Sc7). The function repeats the process in steps Sc6 and Sc7until the 3D-H protrudes from the volume data (step Sc8).

The 3D-ROI determination function determines the position of the 3D-ROIin the volume data based on the distance from the screen of the VR imageto the center of the 3D-R at which the calculated difference between thesums of voxel values is the maximum (step Sc9). FIG. 13 is a graphshowing the differences between the sum of voxel values inside the 3D-Rand that inside the 3D-H corresponding to the distances from the screenof the VR image to the center of the 3D-R along the line-of-sightdirection, as well as the distances corresponding to the maximum valueof the difference for the determination of a 3D-ROI position. The graphin FIG. 13 shows a curve 183 obtained by plotting the 3DR voxel sumscorresponding to the distances from the screen of the VR image along theline-of-sight direction. Reference symbol DM denotes the maximum valueof the difference value; and Py, the distance from the screen of the VRimage along the line-of-sight direction, which corresponds to DM. Thethree-dimensional region-of-interest determination unit 45 determinesthe position of the 3D-ROI in the volume data based on Py.

According to the above arrangement, the following effects can beobtained.

This ultrasonic diagnosis apparatus can determine a 3D-ROI including atarget region when regions larger than the 3D-ROI including large voxelvalues exist in front or back of the 3D-ROI in the line-of-sightdirection. In addition, setting a 2D-ROI on one projected imageincluding a target region will determine a 3D-ROI including the targetregion in the volume data. Therefore, the interpreting doctor or thelike is only required to designate a 2D-ROI on one projected imageincluding a target region. This greatly reduces the operation load onthe doctor or the like. In addition, since the interpreting doctor orthe like performs the above operation on a displayed image, he/she neednot grasp the sequential correspondence between three-dimensional imagesand two-dimensional images. This prevents the interpreting doctor or thelike from being confused. As described above, this apparatus can improvethe operability and operation efficiency for the interpreting doctor orthe like and allows him/her to easily and quickly determine a 3D-ROI.

Fourth Embodiment

The fourth embodiment will be described below with reference to theviews of the accompanying drawing.

The difference from the first to third embodiments is that a 3D-ROI isdetermined based on two different line-of-sight directions.

FIG. 14 is a block diagram showing the arrangement of an ultrasonicdiagnosis apparatus according to the fourth embodiment.

The constituent elements of the first to third embodiments which operatedifferently, a first straight line generating unit 38, and a secondstraight line generating unit 40 will be described below. Note that whenthe technical idea of this ultrasonic diagnosis apparatus is to beimplemented by a medical image processing apparatus, the apparatus has,for example, the arrangement enclosed by the dotted line in FIG. 14.

The first straight line generating unit 38 sets the first point on thefirst VR image generated by a projected image generating unit 29 inaccordance with the instruction issued by the user via an input device33, and generates the first straight line with the first point and thefirst line-of-sight direction used to generate the first VR image. Aninternal storage device 49 stores the position information of the firststraight line in the volume data.

The second straight line generating unit 40 sets the second point on thesecond VR image generated by the projected image generating unit 29 inaccordance with the instruction issued by the user via an input device33, and generates the second straight line with the second point and thesecond line-of-sight direction used to generate the second VR image. Theinternal storage device 49 stores the position information of the secondstraight line in the volume data.

A three-dimensional region-of-interest determination unit 45 generatesthe first and second straight lines on volume data. When these straightlines have a relationship of a skew position, the three-dimensionalregion-of-interest determination unit 45 determines a predeterminedinternally dividing point with respect to the shortest distance betweenthese straight lines as the position of a 3D-ROI. The skew position is astate of non-crossing and non-parallelism associated with the first andthe second straight line in a three-dimensional space. The predeterminedinternally dividing point is, for example, the midpoint of the shortestdistance. When these straight lines intersect each other, thethree-dimensional region-of-interest determination unit 45 determinesthe intersection of these straight lines as the position of the 3D-ROI.

The operation of a function of determining a 3D-ROI (to be referred toas a 3D-ROI determination function hereinafter) in volume data in thisultrasonic diagnosis apparatus will be described next with reference tothe flowchart shown in FIG. 15.

The processing in steps Sd4 to Sd10 which differs from that in FIG. 4which is a flowchart associated with the first embodiment will bedescribed below.

The projected image generating unit 29 generates the first VR imagebased on volume data and the first line-of-sight direction set by theuser via the input device 33. The 3D-ROI determination function sets thefirst point on the first VR image in accordance with the instructionissued by the user via the input device 33 (step Sd4). This functiongenerates the first straight line with the first line-of-sight directionand the first point (step Sd5). FIG. 16A shows a first straight line1stl generated by a first straight line generating unit 38, togetherwith a first VR image 1stVR and a first point 1stP.

The projected image generating unit 29 generates the second VR imagebased on volume data and the second line-of-sight direction set by theuser via the input device 33. The 3D-ROI determination function sets thesecond point on the second VR image in accordance with the instructionissued by the user via the input device 33 (step Sd6). This functiongenerates the second straight line with the second line-of-sightdirection and the second point (step Sd7). FIG. 16B shows a secondstraight line 2ndl generated by the second straight line generating unit40, together with a second VR image 2ndVR and a second point 2ndP.

The three-dimensional region-of-interest determination unit 45determines whether the first and second straight lines have therelationship of the skew position (step Sd8). If the first and secondstraight lines have the relationship of the skew position, thethree-dimensional region-of-interest determination unit 45 determines apredetermined internally dividing point with respect to the shortestdistance between the first and second straight lines as the position ofa 3D-ROI (step Sd9). If the first and second straight lines do not havethe relationship of the skew position, i.e., the first and secondstraight lines intersect each other, the three-dimensionalregion-of-interest determination unit 45 determines the intersection ofthe first and second straight lines as the position of a 3D-ROI (stepSd10). FIG. 16C shows that a 3D-ROI is determined when the first andsecond straight lines have the relationship of the skew position.Referring to FIG. 16C, reference symbol L denotes the shortest distancebetween the first straight line 1stl and the second straight line 2ndl;and 3DP, the midpoint of L which is the center of the 3D-ROI. FIG. 16Cshows a 3D-ROI in a spherical shape as an example.

According to the above arrangement, the following effects can beobtained.

According to this ultrasonic diagnosis apparatus, setting one point ineach of target regions on two projected images based on differentline-of-sight directions will determine a 3D-ROI including the targetregion in the volume data. Therefore, the interpreting doctor or thelike is only required to designate one point on the two projected imageseach including a target region. This greatly reduces the operation loadon the doctor or the like. In addition, since the interpreting doctor orthe like performs the above operation on a displayed image, he/she neednot grasp the sequential correspondence between three-dimensional imagesand two-dimensional images. This prevents the interpreting doctor or thelike from being confused. As described above, this apparatus can improvethe operability and operation efficiency for the interpreting doctor orthe like and allows him/her to easily and quickly determine a 3D-ROI.

Fifth Embodiment

The fifth embodiment will be described below with reference to the viewsof the accompanying drawing.

A medical image diagnosis apparatus according to the fifth embodimenthas the arrangement enclosed by the dotted line in FIG. 1. When, forexample, the medical image diagnosis apparatus is an X-ray computedtomography (to be referred to as a CT hereinafter) apparatus, the X-rayCT apparatus has the arrangement enclosed by the dotted line. Note thatthe medical image diagnosis apparatus may be an X-ray diagnosisapparatus, nuclear magnetic resonance apparatus, positron emissioncomputed tomography apparatus, or single photon emission computedtomography apparatus. In addition, the medical image diagnosis apparatusof this embodiment may be any type of apparatus as long as it is amedical image diagnosis apparatus which generates volume data.

The operation of a function of determining a 3D-ROI (to be referred toas a 3D-ROI determination function hereinafter) in volume data in thismedical image diagnosis apparatus will be described next with referenceto the flowchart shown in FIG. 17.

A volume data generating unit 27 generates volume data (step Se1). The3D-ROI determination function generates a VR image based on thegenerated volume data and the input predetermined line-of-sightdirection (step Se2). This function sets a 2D-ROI on the VR image inaccordance with the instruction issued by the user via an input device33 (step Se3). The process in steps Se4 to Se9 corresponds to theprocess in steps Sa5 to Sa10 in FIG. 4.

According to the above arrangement, the following effects can beobtained.

According to this medical image diagnosis apparatus, setting a 2D-ROI onone projected image including a target region will determine a 3D-ROIincluding the target region in the volume data. Therefore, theinterpreting doctor or the like is only required to designate a 2D-ROIon one projected image including a target region. This greatly reducesthe operation load on the interpreting doctor or the like. In addition,since the interpreting doctor or the like performs the above operationon a displayed image, he/she need not grasp the sequentialcorrespondence between three-dimensional images and two-dimensionalimages. This prevents the interpreting doctor or the like from beingconfused. As described above, this apparatus can improve the operabilityand operation efficiency for the interpreting doctor or the like andallows him/her to easily and quickly determine a 3D-ROI.

Sixth Embodiment

The sixth embodiment will be described below with reference to the viewsof the accompanying drawing.

A medical image diagnosis apparatus according to the sixth embodimenthas the arrangement enclosed by the dotted line in FIG. 7. When, forexample, the medical image diagnosis apparatus is an X-ray CT apparatus,the X-ray CT apparatus has the arrangement enclosed by the dotted line.Note that the medical image diagnosis apparatus may be an X-raydiagnosis apparatus, nuclear magnetic resonance apparatus, positronemission computed tomography apparatus, or single photon emissioncomputed tomography apparatus. In addition, the medical image diagnosisapparatus of this embodiment may be any type of apparatus as long as itis a medical image diagnosis apparatus which generates volume data.

The operation of a function of determining a 3D-ROI (to be referred toas a 3D-ROI determination function hereinafter) in volume data in thismedical image diagnosis apparatus will be described next with referenceto the flowchart shown in FIG. 18.

After step Se3, the processing in steps Sf4 to Sf8 corresponds to theprocessing in steps Sb5 to Sb9 in FIG. 8.

According to the above arrangement, the following effects can beobtained.

According to this medical image diagnosis apparatus, setting a 2D-ROI onone projected image including a target region will determine a 3D-ROIincluding the target region in the volume data. Therefore, theinterpreting doctor or the like is only required to designate a 2D-ROIon one projected image including a target region. This greatly reducesthe operation load on the interpreting doctor or the like. In addition,since the interpreting doctor or the like performs the above operationon a displayed image, he/she need not grasp the sequentialcorrespondence between three-dimensional images and two-dimensionalimages. This prevents the interpreting doctor or the like from beingconfused. As described above, this apparatus can improve the operabilityand operation efficiency for the interpreting doctor or the like andallows him/her to easily and quickly determine a 3D-ROI.

Seventh Embodiment

The seventh embodiment will be described below with reference to theviews of the accompanying drawing.

A medical image diagnosis apparatus according to the seventh embodimenthas the arrangement enclosed by the dotted line in FIG. 7. When, forexample, the medical image diagnosis apparatus is an X-ray CT apparatus,the X-ray CT apparatus has the arrangement enclosed by the dotted line.Note that the medical image diagnosis apparatus may be an X-raydiagnosis apparatus, nuclear magnetic resonance apparatus, positronemission computed tomography apparatus, or single photon emissioncomputed tomography apparatus. In addition, the medical image diagnosisapparatus of this embodiment may be any type of apparatus as long as itis a medical image diagnosis apparatus which generates volume data.

The operation of a function of determining a 3D-ROI (to be referred toas a 3D-ROI determination function hereinafter) in volume data in thismedical image diagnosis apparatus will be described next with referenceto the flowchart shown in FIG. 19.

After step Se3, the processing in steps Sf4 to Sf8 corresponds to theprocessing in steps Sc5 to Sc9 in FIG. 11.

According to the above arrangement, the following effects can beobtained.

This medical image diagnosis apparatus can determine a 3D-ROI includinga target region when regions larger than the 3D-ROI including largevoxel values exist in front or back of the 3D-ROI in the line-of-sightdirection corresponding to a projected image. In addition, setting a2D-ROI on one projected image including a target region will determine a3D-ROI including the target region in the volume data. Therefore, theinterpreting doctor or the like is only required to designate a 2D-ROIon one projected image including a target region. This greatly reducesthe operation load on the interpreting doctor or the like. In addition,since the interpreting doctor or the like performs the above operationon a displayed image, he/she need not grasp the sequentialcorrespondence between three-dimensional images and two-dimensionalimages. This prevents the interpreting doctor or the like from beingconfused. As described above, this apparatus can improve the operabilityand operation efficiency for the interpreting doctor or the like andallows him/her to easily and quickly determine a 3D-ROI.

Eighth Embodiment

The eighth embodiment will be described below with reference to theviews of the accompanying drawing.

A medical image diagnosis apparatus according to the eighth embodimenthas the arrangement enclosed by the dotted line in FIG. 14. When, forexample, the medical image diagnosis apparatus is an X-ray CT apparatus,the X-ray CT apparatus has the arrangement enclosed by the dotted line.Note that the medical image diagnosis apparatus may be an X-raydiagnosis apparatus, nuclear magnetic resonance apparatus, positronemission computed tomography apparatus, or single photon emissioncomputed tomography apparatus. In addition, the medical image diagnosisapparatus of this embodiment may be any type of apparatus as long as itis a medical image diagnosis apparatus which generates volume data.

The operation of a function of determining a 3D-ROI (to be referred toas a 3D-ROI determination function hereinafter) in volume data in thismedical image diagnosis apparatus will be described next with referenceto the flowchart shown in FIG. 20.

After step Se2, the processing in steps Sh3 to Sh9 corresponds to theprocessing in steps Sd4 to Sd10 in FIG. 15.

According to the above arrangement, the following effects can beobtained.

According to this medical image diagnosis apparatus, setting one pointin each of target regions on two projected images based on differentline-of-sight directions will determine a 3D-ROI including the targetregion in the volume data. Therefore, the interpreting doctor or thelike is only required to designate one point on the two projected imageseach including a target region. This greatly reduces the operation loadon the interpreting doctor or the like. In addition, since theinterpreting doctor or the like performs the above operation on adisplayed image, he/she need not grasp the sequential correspondencebetween three-dimensional images and two-dimensional images. Thisprevents the interpreting doctor or the like from being confused. Asdescribed above, this apparatus can improve the operability andoperation efficiency for the interpreting doctor or the like and allowshim/her to easily and quickly determine a 3D-ROI.

Each function associated with each embodiment can also be implemented byinstalling programs for executing the corresponding processing in acomputer such as a workstation and expanding them in a memory. In thiscase, the programs which can operate the computer to execute thecorresponding techniques can be distributed by being stored in recordingmedia such as magnetic disks (floppy® disks, hard disks, and the like),optical disks (CD-ROMs, DVDs, and the like), and semiconductor memories.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

1. An ultrasonic diagnosis apparatus comprising: an ultrasonic probe; anultrasonic transmission/reception unit configured to transmit anultrasonic wave to an object and receive a reflected wave correspondingto the transmitted ultrasonic wave from the object via the ultrasonicprobe and to generate a received signal based on the received reflectedwave; a volume data generating unit configured to generate volume databased on the received signal; a projected image generating unitconfigured to generate a projected image based on the volume data and apredetermined line-of-sight direction; a two-dimensionalregion-of-interest setting unit configured to set a two-dimensionalregion of interest on the projected image; a specifying unit configuredto specify a plurality of voxels based on pixels in the two-dimensionalregion of interest and the predetermined line-of-sight direction; acalculation unit configured to calculate a contribution degree of eachof the specified voxels which contributes to a value of the pixels inthe two-dimensional region of interest based on a voxel value andopacity of each of the plurality of voxels; and a three-dimensionalregion-of-interest determination unit configured to determine a positionof a three-dimensional region of interest in the volume data based onthe contribution degree.
 2. The apparatus according to claim 1, furthercomprising: a hue changing unit configured to change hues of voxelsincluded in the three-dimensional region of interest; and a display unitconfigured to display at least one of a projected image and a sliceimage generated based on the voxels whose hues are changed.
 3. Anultrasonic diagnosis apparatus comprising: an ultrasonic probe; anultrasonic transmission/reception unit configured to transmit anultrasonic wave to an object and receive a reflected wave correspondingto the transmitted ultrasonic wave from the object via the ultrasonicprobe and to generate a received signal based on the received reflectedwave; a volume data generating unit configured to generate volume databased on the received signal; a projected image generating unitconfigured to generate a projected image based on the volume data and apredetermined line-of-sight direction; a two-dimensionalregion-of-interest setting unit configured to set a two-dimensionalregion of interest on the projected image; a three-dimensional regionsetting unit configured to set a three-dimensional region including thetwo-dimensional region of interest as a projection with thepredetermined line-of-sight direction; a calculation unit configured tocalculate a sum of voxel values included in a set three-dimensionalregion moved by a predetermined width along the predeterminedline-of-sight direction every time the set three-dimensional region ismoved by the predetermined width; and a three-dimensionalregion-of-interest determination unit configured to determine, as aposition of a three-dimensional region of interest, a position of thethree-dimensional region, in the volume data, in which a sum of thevoxel values is a maximum value.
 4. An ultrasonic diagnosis apparatuscomprising: an ultrasonic probe; an ultrasonic transmission/receptionunit configured to transmit an ultrasonic wave to an object and receivea reflected wave corresponding to the transmitted ultrasonic wave fromthe object via the ultrasonic probe and to generate a received signalbased on the received reflected wave; a volume data generating unitconfigured to generate volume data based on the received signal; aprojected image generating unit configured to generate a projected imagebased on the volume data and a predetermined line-of-sight direction; atwo-dimensional region-of-interest setting unit configured to set atwo-dimensional region of interest on the projected image; athree-dimensional region setting unit configured to set athree-dimensional region including the two-dimensional region ofinterest as a projection with the predetermined line-of-sight directionand a hull surrounding the three-dimensional region; a calculation unitconfigured to calculate a difference between a sum of voxel valuesincluded in a three-dimensional region moved by a predetermined widthalong the predetermined line-of-sight direction and a sum of voxelvalues included in the hull, every time the three-dimensional region ismoved by the predetermined width; and a three-dimensionalregion-of-interest determination unit configured to determine, as aposition of a three-dimensional region of interest, a position of thethree-dimensional region, in the volume data, at which the differencebecomes maximum.
 5. An ultrasonic diagnosis apparatus comprising: anultrasonic probe; an ultrasonic transmission/reception unit configuredto transmit an ultrasonic wave to an object and receive a reflected wavecorresponding to the transmitted ultrasonic wave from the object via theultrasonic probe and to generate a received signal based on the receivedreflected wave; a volume data generating unit configured to generatevolume data based on the received signal; a projected image generatingunit configured to generate a projected image based on the volume dataand a predetermined line-of-sight direction; a first straight linegenerating unit configured to generate a first straight line by settinga first point on a first projected image generated by the projectedimage generating unit and using the first point and a firstline-of-sight direction corresponding to the first projected image; asecond straight line generating unit configured to generate a secondstraight line by setting a second point on a second projected imagegenerated by the projected image generating unit and using the secondpoint and a second line-of-sight direction corresponding to the secondprojected image; and a three-dimensional region-of-interestdetermination unit configured to determine a predetermined internallydividing point with respect to a shortest distance between the firststraight line and the second straight line as a position of athree-dimensional region of interest when the first straight line andthe second straight line include a relationship of a skew position andto determine an intersection of the first straight line and the secondstraight line as a position of a three-dimensional region of interestwhen the first straight line and the second straight line intersect eachother.
 6. A medical image processing apparatus comprising: a volume datagenerating unit configured to generate volume data associated with apredetermined region of an object; a projected image generating unitconfigured to generate a projected image based on the volume data and apredetermined line-of-sight direction; a two-dimensionalregion-of-interest setting unit configured to set a two-dimensionalregion of interest on the projected image; a specifying unit configuredto specify a plurality of voxels based on pixels in the two-dimensionalregion of interest and the predetermined line-of-sight direction; acalculation unit configured to calculate a contribution degree of eachof the specified voxels which contributes to a value of the pixels inthe two-dimensional region of interest based on a voxel value andopacity of each of the plurality of voxels; and a three-dimensionalregion-of-interest determination unit configured to determine a positionof a three-dimensional region of interest in the volume data based onthe contribution.
 7. The apparatus according to claim 6, furthercomprising: a hue changing unit configured to change hues of voxelsincluded in the three-dimensional region of interest; and a display unitconfigured to display at least one of a projected image and a sliceimage generated based on the voxels whose hues are changed.
 8. A medicalimage processing apparatus comprising: a volume data generating unitconfigured to generate volume data associated with a predeterminedregion of an object; a projected image generating unit configured togenerate a projected image based on the volume data and a predeterminedline-of-sight direction; a two-dimensional region-of-interest settingunit configured to set a two-dimensional region of interest on theprojected image; a three-dimensional region setting unit configured toset a three-dimensional region including the two-dimensional region ofinterest as a projection with the predetermined line-of-sight direction;a calculation unit configured to calculate a sum of voxel valuesincluded in a three-dimensional region moved by a predetermined widthalong the predetermined line-of-sight direction every time the setthree-dimensional region is moved by the predetermined width; and athree-dimensional region-of-interest determination unit configured todetermine, as a position of a three-dimensional region of interest, aposition of the three-dimensional region, in the volume data, in which asum of the voxel values is a maximum value.
 9. A medical imageprocessing apparatus comprising: a volume data generating unitconfigured to generate volume data associated with a predeterminedregion of an object; a projected image generating unit configured togenerate a projected image based on the volume data and a predeterminedline-of-sight direction; a two-dimensional region-of-interest settingunit configured to set a two-dimensional region of interest on theprojected image; a three-dimensional region setting unit configured toset a three-dimensional region including the two-dimensional region ofinterest as a projection with the predetermined line-of-sight directionand a hull surrounding the three-dimensional region; a calculation unitconfigured to calculate a difference between a sum of voxel valuesincluded in the a three-dimensional region moved by a predeterminedwidth along the predetermined line-of-sight direction and a sum of voxelvalues included in the hull, every time the three-dimensional region ismoved by the predetermined width; and a three-dimensionalregion-of-interest determination unit configured to determine, as aposition of a three-dimensional region of interest, a position of thethree-dimensional region, in the volume data, at which the differencebecomes maximum.
 10. A medical image processing apparatus comprising: avolume data generating unit configured to generate volume dataassociated with a predetermined region of an object; a projected imagegenerating unit configured to generate a projected image based on thevolume data and a predetermined line-of-sight direction; a firststraight line generating unit configured to generate a first straightline by setting a first point on a first projected image generated bythe projected image generating unit and using the first point and afirst line-of-sight direction corresponding to the first projectedimage; a second straight line generating unit configured to generate asecond straight line by setting a second point on a second projectedimage generated by the projected image generating unit and using thesecond point and a second line-of-sight direction corresponding to thesecond projected image; and a three-dimensional region-of-interestdetermination unit configured to determine a predetermined internallydividing point with respect to a shortest distance between the firststraight line and the second straight line as a position of athree-dimensional region of interest when the first straight line andthe second straight line include a relationship of a skew position andto determine an intersection of the first straight line and the secondstraight line as a position of a three-dimensional region of interestwhen the first straight line and the second straight line intersect eachother.
 11. A medical image diagnosis apparatus comprising: a volume datagenerating unit configured to generate volume data associated with apredetermined region of an object; a projected image generating unitconfigured to generate a projected image based on the volume data and apredetermined line-of-sight direction; a two-dimensionalregion-of-interest setting unit configured to set a two-dimensionalregion of interest on the projected image; a specifying unit configuredto specify a plurality of voxels based on pixels in the two-dimensionalregion of interest and the predetermined line-of-sight direction; acalculation unit configured to calculate a contribution degree of eachof the specified voxels which contributes to a value of the pixels inthe two-dimensional region of interest based on a voxel value andopacity of each of the plurality of voxels; and a three-dimensionalregion-of-interest determination unit configured to determine a positionof a three-dimensional region of interest in the volume data based onthe contribution.
 12. The apparatus according to claim 11, furthercomprising: a hue changing unit configured to change hues of voxelsincluded in the three-dimensional region of interest; and a display unitconfigured to display at least one of a projected image and a sliceimage generated based on the voxels whose hues are changed.
 13. Amedical image diagnosis apparatus comprising: a volume data generatingunit configured to generate volume data associated with a predeterminedregion of an object; a projected image generating unit configured togenerate a projected image based on the volume data and a predeterminedline-of-sight direction; a two-dimensional region-of-interest settingunit configured to set a two-dimensional region of interest on theprojected image; a three-dimensional region setting unit configured toset a three-dimensional region including the two-dimensional region ofinterest as a projection with the predetermined line-of-sight direction;a calculation unit configured to calculate a sum of voxel valuesincluded in the three-dimensional region; and a three-dimensionalregion-of-interest determination unit configured to determine a positionof a three-dimensional region of interest in the volume data based onthe sum of the voxel values.
 14. A medical image diagnosis apparatuscomprising: a volume data generating unit configured to generate volumedata associated with a predetermined region of an object; a projectedimage generating unit configured to generate a projected image based onthe volume data and a predetermined line-of-sight direction; atwo-dimensional region-of-interest setting unit configured to set atwo-dimensional region of interest on the projected image; athree-dimensional region setting unit configured to set athree-dimensional region including the two-dimensional region ofinterest as a projection with predetermined line-of-sight direction anda hull surrounding the three-dimensional region; a calculation unitconfigured to calculate a difference between a sum of voxel valuesincluded in the three-dimensional region and a sum of voxel valuesincluded in the hull; and a three-dimensional region-of-interestdetermination unit configured to determine a position of athree-dimensional region of interest in the volume data based on thedifference.
 15. A medical image diagnosis apparatus comprising: a volumedata generating unit configured to generate volume data associated witha predetermined region of an object; a projected image generating unitconfigured to generate a projected image based on the volume data and apredetermined line-of-sight direction; a first straight line generatingunit configured to generate a first straight line by setting a firstpoint on a first projected image generated by the projected imagegenerating unit and using the first point and a first line-of-sightdirection corresponding to the first projected image; a second straightline generating unit configured to generate a second straight line bysetting a second point on a second projected image generated by theprojected image generating unit and using the second point and a secondline-of-sight direction corresponding to the second projected image; anda three-dimensional region-of-interest determination unit configured todetermine a predetermined internally dividing point with respect to ashortest distance between the first straight line and the secondstraight line as a position of a three-dimensional region of interestwhen the first straight line and the second straight line include arelationship of a skew position and to determine an intersection of thefirst straight line and the second straight line as a position of athree-dimensional region of interest when the first straight line andthe second straight line intersect each other.
 16. A medical imageprocessing apparatus comprising: a storage unit configured to storevolume data associated with an object; a projected image generating unitconfigured to generate a projected image comprising a plurality ofprojection pixels respectively corresponding to a plurality ofprojection lines from the volume data; and a calculation unit configuredto calculate a contribution degree of each of a plurality of voxels on aspecific projection line corresponding to at least one specificprojection pixel of the projection pixels, the contribution degree is adegree in which a voxel value of each of the voxels contributes to apixel value of the specific projection pixel, based on at least one ofan accumulated value of voxel values associated with a voxel located onone of two sides of each of the voxels on the specific projection lineand an accumulated value of voxel values associated with a voxel locatedon the other of the two sides.